Sewing-machine.



ci E. FRANCIS! SEWING MACHINE. APRucATloN FILED APR. ls. 191.1.

CHARLESEDWAR'D FRANCIS, 0F I-IOLLOVVi-KY, LONDON, ENGLAND, ASSIN-OR Td VICKERS .LI-ILVII'JIEID,01E"WFSTIVIIINSTER,l GLAND. .i

sWING-MACHINE. y

T all whom z't'mag/ tonteria." l

Be it lmown that I, CHARnEs EDWARD FRANCIS, af subject of the King ofGr'eat ai non-rotary bobbin case within!V it in which the bobbin for the' bobbinA thread is arranged, and the object of the said invention is to provide' stitch forming* means that shallbe suitable in designy for work of practicallyv all characters from the lightest material and finest thread to thel heaviest material and lcoa-rsest thread usuallydealt with in machines`r of-"the kindv Vreferred to and also' snchthat inthe same machine a wider rangel of workmay be performed than heretoforeinl machines of the said' kind;` In' other words the mainI object of. thepresent- ,invention is'l to' combine the respective ad# vafntagesl in known inachinesy of the said kind` wherein thefrotary hook makes* one revolution for each stitch and thosein" which the saidf hookfma'kes two revolutions-'for each stitch and those in whichr theS said hook makes three revolutions for each stitchand so to providef a stitch forming mechanism which as a type is equally well suited' for use in a domestic sewing. machine or in a sewing machine for factory use and for operating onE light or heavy/fabrics, leather or the like andlwh-ich also will `enable the .sa-me individual machine to operate on a' larger range of character of work than heretofore.

Accordingto` the said invention the outer part of the bobbin case and theQ inner' side'rv of aringholder employed for retain-ingthe bobbin case inx the rotary hook orlooptaker have correspondingv contacting surfaces graduallyfvarying inf contour in the' directionv of rotation of they looptaker, to counteract the tendency .of the bobbincaseto. rotate and rise while permitting proper passagefo'f'r case has peripheral bearing in thev looptakerf toward the inner' the loop. The bobbinf side thereof andthe .bobbin case alsofha's" a .radial projection or lugs directly iii-.front of in the county of London, England',l have invented certain new and useful ImL Patented oet. a, i917;

Application med Apr`i11s,19'17. serarivo; 162,866.

a needle-aperture in the saidv case the said lug having 'an' eye through which the `bobbin' .tread led upwardly 'to the needle hole mythe-throat platel outof the path of the looptaker,'the innerfaceof the said: lug

ybeing adapted to assistf in forming the loopv to' bes engaged by thelooptaker. Tl1e"bob' bin thread may pass overthe outer facelof the' said lugiand thetension' on the said'- thread may' conveniently' be obtained's-by a tension' springV on' the" outer part of the' bob-y bin case bearingon the thread;I itp'asses over the youter face of the "said lug. ln con-l sequen'c'efof the construction described the' needle aperture inl the bobbinI case'maybe so sitnated that theneedle'descends therein" infa planev outside ,the bobbin so thatthe latter cannot be injured `by the `needle 'if imperfectly secured'.- The said invention is4 hereinafter "inore particularly described with lreference to theaccompanying drawings which illustrate the preferredemb:odinient` thereof.- p Y The invent-'ion is"` illstrated in the accornl-` panying drawings, in which l t 1 Figurel of the"said vdrawingsis,` anend elevation ofV part ofthe head off a sewing; machine" showingY the `relative positions of the' needle' and; the' hookv when the, hook point isl entering ,the loop' forined by` the needle thread. l I Fig; 2 isa` plan* View of thehook in the position shown in Fig.` 1,- the needle being.

shown in s'ectionl. v l

Fig. 3 shhwssectionall views of the hook' onv the line X'QXV of Fig.) lthe bridgeI piece hereinafter referred tol being' omitted. Figs. 4 and 5 show the Vbrid'gefpiece in si'de elevation and plan View respectively. c Figsi 6" and `7 show the bobbin in end el'eyation and sideviewrespectivelyl` y, Fig'iS shows-the bobbin case in elevationH from the ba'cl'r, e., the open end;

Fig. 9isafs'ide elevation'ofsaine.; Fig. 110v is aI section'I onv line Y-Y of Fig.l` 8, looking towardk the" right ;`4 and l Fig. 11 is a front View of the bobbiny case", Fig.v8 Q

Figs". l2' and 13* are y p i sidev and front elevations'respeetilvely of the bobbinlcase tensionl spring (not shown in Figs. 8-11). Fig. 'l'is ajplanview of Fig. 8 with: the bobb'i'n-fcasertens'infspring y in position;

. throat plate.

Fig. 15 is an inner end elevation of the bobbin-case holding ring.

Fig. 1G is a side elevation of same.

Referring to the drawings:

The hook or looptaler rotates once only for each stitch and is a cup-shaped body A rigidly mounted on a rotatable shaft B-to which variable motion is imparted-and having an outwardly inclined loop-taking point c formed on its rim. The edge or face of the said rim lies in one plane for rather more than half the periphery, the remainder being set back, as shown at a to allow the loopl to pass freely around the bobbin-case, and the loop-taking point a is formed on the portion of the rim first referred to by cutting away a portion of the cup-like shell, one edge a2 of the gap thus formed constituting the outwardly inclined side of the hook point while the opposite edge a3 is substantially parallel thereto. This gap is much wider than the gap in the known hooks of similar construction and is bridged by a raised bridge piece C that serves to control the loop. Vithin the hook body a seating D is formed for a peripheral rib e that is formed approximately centrally on the bobbin-case E and extends around approximately two thirds of its periphery, and the bobbin-case is held up to the said seating when the machine is working partly by the pull on the bobbin thread and partly by the bobbin-case holding ring F hereinafter described.

The bobbin Gr is carried in the bobbincase on a central pin or stud in substantially the usual manner. 4

The bobbin-case E is so constructed and arranged that the bobbin thread is drawn up in to the work from a point which is in the same vertical plane as the needle hole in the throat plate of the machine and situated outside the path ofthe hook point so that the bobbin` thread does not require to be deiiected out of the path of the hook. The said point is a point e situated on a projection or lug e2 on the outer or closed end of the bobbin-case, which lug extends radially beyond the periphery of the case about centrally of that portion of same over which the peripheral rib e does not extend. rThe bobbin thread is led from the bobbin through guide slot e3 and a guide lchannel ec in the bobbin case to the lug e2 and drawn into an eye formed therein at the point e', and from the said eye it passes up between the outer face of the lugy e2 and a tension spring H to the needle hole in the The inner face of the lug e2 assists in forming the loop to be engaged'by the hook by preventing the formation of a loop at the opposite side of the needle to the hook.

The tension spring H is engaged in a shallow vertical groove formed inthe outer face of the lug e2 and is secured on the closed end of the bobbin case by a screw which is engaged in a threaded hole 7L in the end of the bobbin stud and which serves also for adjusting the tension on the bobbin thread. The usual arrangement of the tension spring on the bobbin-case has the defect that it necessitates the employment of very small screws as they are engaged in holes in the thin shell of the bobbin-case. rllhe arrangement for applying the tension to the bobbin thread has further advantages in that it permits the thread to be drawn oif perfectly smoothly without any tendency to raise the spring from its seat, and that the tension can be readily adjusted while the bobbin-case is in position, without even turning back the ring holder.

The needle descends directlyat the back lof the lug e2 into an aperture e5 formed in the periphery of the bobbin case at that point. At the edgerof the aperture e5, opposite to the lug e2, an upstanding lip e? is preferably formed, which lip assists vin maintaining the bobbin `ease in its normal position `within the hook.

The tendency of the bobbin case Eto rotate with the hook is counteracted by the shape of the contacting surfaces of the outer flange of the bobbin case and the ring holder F. The lug e2 engages loosely inthe vertical slot or groove, indicated in the drawing by the reference letter f, in the face of the ring, but the engagement must be suchA that the loop can readily pass between the lug and the recess when being drawn up into the work rotation of the bobbin case being prevented by the formation of the aforesaid contacting surfaces. The ring holder F is preferably hingedly mounted so that it can be readily turned back to allow the-bobbin-case to be removed, 'and it is also preferably adjustable to permit of regulating its yposition relatively to the bobbin-case. .The-

contacting surfaces of the bobbin-case and the ring holder are beveled and somewhat rounded to insure the ready passage of the loop but the rounded beveled portions gradually change in contour in the direction of rotation of the looptaker, and the ring holder being correspondingly shaped the tendency of the case torise when the bobbin thread is pulled and-to rotateis counteracted.

What I claim and desire to secure by Letters Patent of the United States is 1. l'n a lock stitch sewing machine, the

combination with a rotary hook, of a bobbin case withinthe same, a ring holder for said case, the said case and holder having corre-v sponding contacting faces of gradually variable contour in thedirection of rotation ofv the hook, said bobbiii case having a needle aperture therein, a radial projection. on the case directly in front of said aperture, said projection having an eye therein through which the bobbin thread is led upwardly to the needle holein the throat plate, the projection being so situated that the needle thread contacts with its inner'face to help forni the loop to be engaged by the rotary hook.

2. In a lock stitch sewing machine, the combination with a rotary hook, of a bobbin case within the same, a ring holder for said case, the said case and holder having corresponding contaoting faces of gradually variable contour in the direction of rotation of the hook, said bobbin case having a needle aperture therein,a radial projection on the case directly in front of said aperture, said projection having an eye therein through which the bobbin thread is led upwardly to the needle hole in the throat plate, the projection being so situated that the needle v In testimony whereof, I herewith aiiix my` signature.

CHARLES EDWARD FRANCIS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. C. v 

